Getting a slight sense that it is indeed odd but possibly influenced by the prominence of "se trouver" in this construction. By comparison nothing strikes me as odd about "Comment est-ce qu'il est ?" except wordiness. Instincts may be off.
– Luke SawczakJun 13 '18 at 13:23

It's grammatically correct, but I would use a synonym to the verb être in order to sound less weird.. Like.. Où est-ce que ma chaise se trouve ?
– alecailJun 13 '18 at 18:31

7

Speaking as a native, I disagree with the statement that “Où est-ce que ma chaise est” is correct. It's comprehensible, but it sounds weird, I wouldn't say that, and I'd be surprised to hear a native say it.
– Gilles♦Jun 13 '18 at 21:32

assuming i'm not mistaken, none of the grammar books for French Learners give any rule that could create "Où est-ce qu'est ma chaise?" !
– silphJun 13 '18 at 14:29

1

Maybe, but it does not seem wrong to me. Rules and books are nice, but they do not cover everything, especially slang.
– Hawker65Jun 13 '18 at 14:36

1

I agree with Hawker65, rules in books are nice to learn how to speak correctly but they don't cover everything. They contain mostly general cases. Your question is hard to answer. My answer, to be honest, is opinion and experience based. This is why I said as a native. Où est-ce que ma chaise est? is apparently correct but not very used (in France Metropolitaine at least).
– guillau4Jun 13 '18 at 15:07

No, “Où est-ce que ma chaise est?” is not correct French. I don't have a grammatical explanation for it, just my native intuition. It sounds weird, I wouldn't expect a native speaker to say it. I think the weirdness comes from having the verb être at the end of the sentence, which apparently clashes with the fact that être always requires a complement (except in philosophy).

For yes/no questions, in informal spoken French, the verb-subject-complement syntax feels stilted and wouldn't be used, leaving a choice of “est-ce que” and using intonation only to convey that the sentence is a question. For questions that start with a question adverb, the adverb-verb-subject-complement syntax is sometimes acceptable in informal spoken French. You can ask “Où est ma chaise ?” in informal spoken French. In contrast “Où vas-tu ?” is ok but a bit formal, and “Quand viens-tu ?” is very formal. I don't have a grammatical explanation for this strange difference.

In informal spoken French, you can use the adverb-subject-verb order when the subject is a pronoun. Since informal spoken french lets you use a pronoun and put its antecedent after it in the same sentence, this doesn't limit what you can express this way.

"Ma chaise est où?" is not correctformal. If you want to ask a question, you need to inverse the verb and the noun : "Où est ma chaise?", like you said.

You can ask questions without the question mark, these are called "Phrase interrogative passive (ou indirecte)" or something really close to that. For example : "J'aimerais savoir où se trouve ma chaise." is a question, "without a question".

If you want more advice regarding "est-ce que", you can follow this link.

"Où est-ce que tu vas?" and "Où est-ce que ma chaise est?" are both incorrect. In a direct interrogation sentence, as I said earlier, verb and noun need to be reversed. It is not the case here, as "tu" comes before "vas" and "ma chaise" comes before "est".

We could try to flip this direct interrogation to an indirect interrogation, but in this case, as pointed in the link I... linked.. earlier, you cannot use "est-ce que" in an indirect interrogation.

"Ma chaise est où?" is correct informal spoken French. “Où est-ce que tu vas?” is correct spoken or written French. “Où vas-tu?” is one correct (formal) way to phrase the question but it is not the only one.
– Gilles♦Jun 13 '18 at 21:31

I agree my first sentence might be confusing, I wrote the last sentence of my answer to specify I was speaking of a formal context. I would also like to know why do you think "Où est-ce que tu vas" is formal. I might be wrong, but I've had pretty extensive french classes at university.
– IEatBagelsJun 14 '18 at 12:26